Just like nylon, polyester is also a kind of plastic or 100% man-made synthetic fabric. However, it has a different chemical name and is not in the same way of production as compared with nylon. Polyester fabric is less industrially used than nylon as well. But it’s a tough and abrasion-resistant textile.
Polyester flags, hence, are very strong, wrinkle and mildew resistant, quick-drying, and smooth. Most of them are sewn precisely; even the embroidered stars are made. They are best used in a high-wind area and unpleasant weather conditions. This advantage sets them apart from nylon flags that can be quickly deteriorated by heavy winds. Nevertheless, avoid flying them from house-mounted poles because polyester fabric seems not so lightweight enough to keep the pole from being unbroken.